Diagonals of a rhombus are 1 metre and 1.5 metres in length. The area of the rhombus is:

The correct choice is: “0.75 m²”

The diagonals of a rhombus bisect each other at right angles, splitting it into four congruent right triangles. So the area of a rhombus is half the product of its diagonals: Area = ½ × d₁ × d₂ = ½ × 1 × 1.5 = 0.75 m².

“1.5 m²” is the product of the diagonals without halving, “3 m²” doubles it, and “0.375 m²” halves it twice.